Why are group 1 metals called alkali metals?
They form an alkaline solution when they react with water
Why do alkali metals have similar chemical properties?
They have one electron on their outer shell
Properties of alkali metals?
soft (can easily be cut with a knife)
low density
low melting point
very reactive (only needs to lose 1 electron to become stable)
Trends of alkali metals?
melting point decreases as you go down the group due to decreasing attractive forces between outer shell electrons and positive ions
softer as you move down
reactivity increases
Why does reactivity of alkali metals increase as you go down the group?
the outer shell electrons get further away from nucleus so there are weaker forces of attraction between them
less energy is needed to overcome the forces of attractions so outer electron is lost more easily
Why are alkali metals stored in oil?
They react readily with oxygen and water vapour in the air
What is produced when an alkali metal reacts with water?
Metal hydroxide + Hydrogen
Chemical equation for the reaction between sodium and water?
2Na (s) + 2H20 (l) --> 2NaOH (aq) +H2 (g)
What is formed when alkali metals react with oxygen?
Metal oxide
Reaction between Lithium and Oxygen
4Li + O2 --> 2Li2O
What is formed when alkali metals react with Chlorine?
Metal chloride
Reaction between Lithium and Chlorine?
2Li + Cl2 --> 2LiCl
What are group 0?
Noble gases
Properties of noble gases?
inert
low density
low boiling/melting point
Meaning of inert? Why are noble gases inert?
unreactive
they have a full outer shell of electrons
Trends of noble gases
Boiling points increase as you go down due to an increase in atomic mass so more intermolecular forces that need more energy to break
Group 7 elements
Halogens
Properties of halogens
poisonous
non-metals
diatomic
reactive
increasing melting point
Why do the melting points of halogens increase as you go down the group?
increasing intermolecular forces so more energy needed to break them
Fluorine at room temp
yellow gas
Chlorine at room temp
pale green gas
Bromine at room temp
red-brown liquid orange in solution
Iodine at room temp
purple-black solid dark brown in solution
What are the halogens states on room temp?
fluorine and chlorine - gas
bromine - liquid
iodine - solid
Why do halogens have different states?
They have different melting and boiling points
Why does reactivity of halogens decrease as you go down?
the forces of attraction between the nucleus and outer shell decreases so harder for atoms to gain an electron
Properties of transition metals
hard and strong
lustrous
good conductors of heat and electricity
highly dense metals
very high melting points
What do transition metals form?
colourful compounds
Which elements aren't transition metals and why?
Scandium and Zinc - they don't form colourful compounds
Transition metals can be used as ..
catalysts like in the haber process with iron